Color ramp with displacement node problem
When you are shifting the color ramp tabs like you do in the 2nd picture, what you are doing is telling blender to make most of the texture either black or white with only a little bit of greys in the middle. Only the colors that are mid-grey will remain grey, every other color will become either black or white.

The problem with this in this case is that, for displacement, blender interprets black as the very low and white as the very top. Lots of black means lots of low aid lots of white means lots of peaks with very little in between. If what you want is to make the peaks less high, what you want to do instead is make the whites less white. Change the white tab on your color ramp to a grey and the peaks will be lower. The darker the grey, the lower the peaks.

light grey peaks:

mid grey peaks:

dark grey peaks: